


Biotale

by YaoiAddiction



Category: BioShock, Undertale (Video Game)
Genre: Action, Adventure, Alternate Universe - Canon Divergence, Angst, Death, Determination, Gen, Gore, Minor Character Deaths, Mystery, Story divergence, Voilence, basically everyone in Undertale - Freeform, dust - Freeform, everything you knew about the two universes has changed, lots of death, only listed the important people
Language: English
Status: Completed
Published: 2017-08-19
Updated: 2017-08-19
Packaged: 2018-12-17 08:13:44
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 2,247
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11847540
Author URL: https://archiveofourown.org/users/YaoiAddiction/pseuds/YaoiAddiction
Summary: The Underground was set free by the humans after years of confinement and isolation caused monsters to lose their powers. Everyone lives in a normal society. One lazy skeleton took a plane to go visit his brother, not realizing that his adventure was going to take a nosedive into the ocean below.Based off the game of Bioshock but set in the world of Undertale, this AU attempts to rewrite but stay faithful to worlds its based off of.





	Biotale

 

The world for the skeleton monster known as Sans was bathed in shades of grey. Not even the overhead lights of the plane that carried him across the ocean could change the feeling of dull monotony that threatened to overtake his own thoughts. He fiddled with the end of his hoodie as he watched the clouds slowly roll by from his passenger seat. All around him, monsters and humans alike conversed or slept the trip away, not even bothered by the recent political strain that warred between the two races. Sans didn’t care if the rest of the world burned to the ground, just as long as his brother was happy and healthy.

With a sigh he pulled out his phone and re-checked the message Papyrus had last sent a week ago, asking for his older brother to come visit him in Europe and check out the ruins that had once been their ancestors homes. Never one to deny his brother anything, he bought the quickest ticket he could with the money he had saved up from his job and caught the flight that very day. However he had started to regret the decision as the young human child next to him kept poking his arm to get his attention. 

“Sir? Scoose me sir? Sir!”

Sans sharply turned his skull to face the tiny blonde haired nuisance, sending the best death glare he could muster. “didn’t your parents tell you not to talk to strangers kid?”

With a giggle she shook her head yes and scooted closer to the reluctant monster. “Yeah ‘course they did! But I wanted to ask you someth’in that Mama and Papa won’t tell me.”

Letting out a long drawn sigh, Sans let his glare drop and faced the window again. “fire away i guess…” He could practically feel the child vibrating with excitement.

“Okay okay okay! I wanted to ask choo if monsters can use magic! My friend told me once that his classmate Vicki could summon candy from nowhere! Can you summon candy too?”

“nah kid, and your friends pal was probably just pulling a slight of hand. long ago monsters could use magic but that was generations ago. today we’re all just normal.”

“Aww! I thought it was real!”

With a exaggerated huff the girl leaned back into her stolen seat, crossing her arms in disappointment. Feeling a bit guilty for his attitude towards the innocently curious kid, he abandoned his window and leaned onto his armrest on the right and gave his award winning smile.

“hey, it was real decades ago. skeleton monsters and dog monsters used to be able to summon bones.”

“Really? What kind of bones?” she asked, moving out of her pouting pose and happily bouncing around on her seat once more.

“well skeleton monster bones were pretty ‘humerus’… and dog monsters were all bark no bite.”

The human child blinked in confusion at first, but started giggling hysterically at the second part of his joke. “Ahha! Your really funny Mr. Skeleton!”

A deep chuckle rumbled from his ribcage, sounding more genuine that it had in months. “the name’s Sans the Skeleton.” 

 

* * *

 

 

The rest of the flight was slow and uneventful. Sometimes he felt the little girl poke his arm but otherwise he decided to close his eye sockets and sleep the rest of the ride. Turbulence bounced the plane around but did nothing to awaken the sleeping monster. Sans only finally woke up when he felt gravity start to pull the plane to the ocean below.

Sans had no need to breathe, but he still felt the pull of the current as the rest of the plane started to sink to the bottom. He frantically looked around for any survivors, slowly coming to the realization that everyone else probably got dragged under the ocean. With a silent farewell for the souls of the people he had traveled with, Sans slowly made his way to the top. As his skull broke through the surface, he tried to frantically search for somewhere to stand his ground, and noticed a worn down lighthouse looming in the distance. The giant structure held a symbol that looked more and more familiar the closer he swam, the triangle and wings closely resembling the outdated symbol of the lost royal family. Baffled by this discovery, Sans took one more longing look at the wreckage of the plane before moving his way inside to get away from the beginnings of rain. 

It was almost to dark to see. A mossy gigantic statue of a goat monster took up most of the lighthouse’s interior. The shivering skeleton monster slowly shuffled his way down the stairs driven by pure curiosity. The farther down he went, the more dreary and abused the environment became. After feeling the walls the make it through the nearly pitch black hallway he came across something that vaguely looked like a submarine. He poked his head inside and decided he had explored enough, not seeing any way to really operate the device and wanting to go back and figure out a way to go to his brother, when suddenly a radio attached to the sphere activated in a crackle of old static. Sans jumped in surprise and moved to make a run from the machine until he heard a voice come through.

“bzzt-H-zzztzz-Hello? Is any-btz-one there? Cane someone please help me! Is anyone on this-ckkrtz-channel still alive?”

Against his better judgement, Sans stepped back into the odd submarine and grabbed the radio to respond to the small and weak voice on the other end. “uh… hey? kid you doing okay? whats wrong?”

Silence stretched for an unnaturally long period of time before the voice came back.

“Thank the stars! I-ktztk-don't know who you are but can you please help me? The king is going to bomb the entire Undersea! What section are you in?”

“section? undersea? slow down kid, i don't know where you are. i’m in a lighthouse after a plane crash and i ju-”

“WHAT?” The soft voice that was pleading earlier screamed so loud it startled the poor monster on the other end, causing him to fall back onto one of the cushioned seats lining the inside of the machine. “Your from-btzzzzt-the outside? This is… unexpected. But right now your the only one who can save the rest of us from dying. Can you-tzzhz-please help us? I promise after this is all over you can go back home. I just want to find my mom and dad and save the ones who aren’t crazy. Maybe when you stop-bttz-the bombing you can lead us all back the working pod you found.”

With a sigh Sans moved his cracked hand over his chest and summoned his soul to check his health. He noticed that the fall had caused half of his already abysmal health to drastically decline, leaving some of his bones chipped and dust to slightly leak from the cracks. His gaze shifted to the leaver placed on the side of the submarine, realizing thats what made the entire thing start moving.

“listen, i’ll take the deal so long as i can stay alive to get back to my bro. have anything to heal me down there?”

The relieved gasp on the other end caused Sans to crack a small smile at the hope he heard from the other end. He had a feeling Papyrus would want to help the poor kid no matter what, so he should reach to attempt to do the same.

“Oh! Yeah we have health kits and monster food. I’m sure you’ll be able to heal yourself up as long as your careful! Thank you so much Mr… uhh…”

“names sans the skeleton,” he replied as he used his free hand to pull on the lever.

The sphere burst to life and closed its hatch, rumbling before starting is preset destination under the ocean. As it went deeper and deeper, the voice on the other end of the radio came in more clear, finally letting Sans hear the mystery monsters voice as best as the device would allow.

“My names Asriel, and I’ll make sure you stay alive down here.”

“speaking of down here, where am i going?”

He used the tattered ends of his hoodie to rub away the filth that caked the glass window on the hatch to see outside, eye sockets widening as he took in gigantic structures that looked almost too technologically advanced for the would he lived in. Bridges connected looming towers to each other and lights flickered inside the gigantic buildings that reminded Sans of the crowded city of New York. The farther he traveled, the more the wounded skeleton felt a sense of foreboding from rooms with broken lighting and cracked walls.

“Your heading down to the Undersea, the final stand of monsters against the humans.”

 

* * *

 

 

As the sub finally went through an opening port and resurfaced inside an old docking station, Sans moved over to the lever to open the hatch but the panicked voice from the radio halted his movements. "Wait! Don't open it yet. Theres something dangerous outside! Wait until its gone."

As Asriel warning him, the shape of a smaller monster could be seen from outside the pod. A small reptile monster with small arms hidden in a torn and abused sweater was backing up in fear as something in the shadows advanced closer. The small kid was crying and curling his tail towards himself in self defense, having no where else to run from certain doom. Sans could barely hear the muffled cries of the monster on the other side, causing him to clench his hands in anger.

"let me go out there and save him!"

"You can't! Whatever is out there will kill you too. We'll save everyone else. You have to let him go, I'm so sorry Sans... I wish we could, but..."

Before the shadow advanced, the small monster kid looked behind him to see the shocked face of a friendly monster on the other side. Tears streaked his small face as he started to run towards the submarine, crying for the mystery skeleton to save him. before he could make it to the hatch he tripped on his own feet and fell to the ground. Immediately the shadow emerged into the light and bit into the struggling child's tail. What looked like a mutated dog monster ripped into the flesh of its victim below, the agonizing screams under it's feet going unheard as limbs were torn from the body in a frenzy of rage. As the reptile monsters eyes finally started to die, he took one more look at the monster on the other side of the glass and gave a shaky smile before his entire being broke apart and his soul splintered into pieces. Some strange red liquid flew from the wounds on the dog monster, mixing into the dust below in some horrifying concoction that illuminated the dark room. With a howl of victory and dog ran off, leaving a glowing trail of the mysterious liquid behind. Dust scattered throughout the dock as the hatch was slowly opened. Sans immediately fell to his knees from the lack of support and moved to shakily grasp at the remains of the sweater that was soaked in the strange liquid and small monster's remains.

"i could of... he thought i could save him... i..."

"Sans..." The hesitant voice on the radio on the floor replied with sorrow and sympathy. "I want to save them all too, but we can't. Down here its kill or be killed. The ones who don't know die. I want to save them, but to do that I have to make sure you make it to the king alive. Your our last hope."

With a sad smile he set the ruined clothes down and moved towards a pile of boxes that sat near a strange machine in a dark corner of the docking station. Inside was something like a glowing star that barely gave off any light of its own.

"It's going to hurt, but your going to have to fight those things you saw. These monsters aren't really alive anymore, their souls died a long time ago. All that's left of them are a dripping mess of memories and twisted determination."

The small skeleton pulled a sturdy looking plank from the crates and slowly made his way towards the only exit in sight. Before left, he scooped up any of the former monster's dust he could hold in his small hands and threw them into the water in a makeshift burial.

"are there more like this kid? are there monsters that are still sane in this terrible place?"

"Yes, and I want to save them from this fate. Are you sure you want to do this. You probably have family waiting for you to come home safe..."

Sans stood and properly put the radio away in his hoodie so he could keep the plank steady in his hands. His resolve was set in stone and any more doubts about this journey were washed away as he gazed at the trail left on the ground.

"i can't leave you guys down here to die. my bro will understand, heh, he's always telling me to stop being lazy and do something for once in my life..." A chill ran down his spine as he slowly advanced to the next room. "... so you can count me in."

**Author's Note:**

> Okay... so this is kind of like a pilot chapter originally made for a contest. (New Experiences) As the story would advance the rooms and the characters and environments will always be changing to reflect the world of Undertale but always staying as its own universe. I would love to explore more in the future, but I don't know if I should... so any feedback would be greatly appreciated, but if not I still hope you all enjoyed the story for what it was :)
> 
> If people do want more, I'll change this oneshot into a chaptered thing and I'll get everything written out ahead of time before posting weekly. I don't want this story to be left behind like my other ones, I want to really see this through to the end if I do work on it.


End file.
